Variable capacity fuel injection pump for fuel combustion operated pile driver



March 17, 1970 H. SIGLE 3 500,1

VARIABLE CAPACITY FUEL INJECTION PUMP FOR FUEL COMBUSTION OPERATED FILEDRIVER Filed June 13, 1968 2 Sheets-Sheet l Fig. 1

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combustion chamber March 17, 1970 H. SIGLE 3,500,752 VARIABLE CAPACITYFUEL INJECTION PUMP FOR FUEL v COMBUSTION OPERATED FILE DRIVER FiledJune 13, 1968 2 Sheets-Sheet 2 United States Patent US. Cl. 103-37 3Claims ABSTRACT OF THE DISCLOSURE In combination with a fuel injectiondevice, especially for fuel combustion operable pile drivers, a controldevice which is adjustable each time by equal steps while the fuelinjection device is operable independently of the stroke time and powerof adjustment of said control device.

The present invention concerns a fuel combustion operable pile driverwith a fuel injection pump which is adjustable in conformity with apredetermined deliveryv With pile drivers of the above-mentioned type,the delivery of the pump per stroke which determines the driving energyis, whenever desired, adjusted in an infinitely variable manner. Suchstepless adjusting devices are known according to which the adjustmentis effected by cables, by Bowden wires, or hydraulically.

It has been found that such stepless or infinitely fine adjustment, isunsatisfactory. This is due to the fact that the operator, wheneffecting an operation which is not very precise in view of the factthat it is stroke-dependent, or for other reasons, in numerous instancesdoes not effect the adjustment in conformity with the change in thedriving energy to such an extent that the optimum would be obtained inthe respective instance. When reducing the driving energy to too greatan extent, the pile driver stops, whereas when unduly increasing thedriving energy, the member or object to be driven will be damaged.

It is, therefore, an object of the present invention to remedy theabove-outlined drawbacks.

It is another object of this invention to provide a fuel combustionoperable pile driver with a fuel injection pump in which the delivery ofthe pump can be adjusted so as to yield the optimum result for therespective situation encountered.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawing. FIGURE 1 diagrammatically illustrates a fuel pumpfor use in connection with the pile driver. FIGURE 2 further shows themeans for adjusting the control member which determines the delivery ofthe injection pump.

It has been found, according to the present invention, that theabove-outlined drawbacks will be avoided if means are provided whichbring about that each adjustment can be effected only by short stepswhich cannot be exceeded by any handling, the total adjustment beingadapted to be effected only by a repeated adjustment by such stepgradually and without excessive control. Therefore, in conformity withthe present invention, such fuel combustion ice operable pile drivershave the pump provided with a control device adjustable always by thesame step regardless of the stroke time and force of adjustment.

If with such an adjustment of the delivery of the injection pump perpump stroke, it should be desired that the pile driver energy, whichdoes not vary in conformity with the linear function relative to eachstep, is adjusted as linearly as possible, this may be realizedaccording to a further development of the present invention according towhich the adjusting device is equipped with a cam affect ing theadjusting element of the pump for varying the delivery thereof. Thisarrangement is such that the dependency of the pile driver energy fromthe fuel delivery per pump stroke changes from step to step by the sameamount.

Referring now to the drawing, the latter shows only diagrammatically theinjection pump and the device for moving the adjusting element for thedelivery of the injection pump, said device when being adjusted changingthe delivery per pump stroke (FIG. 1 and FIG. 2).

Fuel passes from a fuel reservoir 11 through a conduit 12 and an inletpassage 13a in the pump housing 13 into the compression chamber proper13b of the pump and also into an adjacent passage having associatedtherewith a check valve 14 set for a certain pressure. In a cylinder 13fwhich forms the continuation of the compression chamber 13b there isreciprocably arranged a plunger 15 adapted to be actuated by a lever 17pivotally supported by a pivot 18. A spring 27 continuously urgesplunger 15 to move outwardly.

Disregarding the delivery adjustment, which will be explained furtherbelow, the fuel displaced by the plunger 15 during its inward movementby lever 17 passes through the check valve 14 and through a conduit 19to the combustion chamber of the fuel combustion operated driver (notshown) where it is burned for the next driving stroke of the driver.

The passage 13c is continued by a passage 13d transverse to the passage130. A control piston 20 is displaceable in the said transverse passage13d.

Passage 13d is closed toward the outside by a dis placeable stopper 21which also seals said passage 13d toward the outside. Stopper 21, bymeans of its inner surface, serves as abutment for the control piston20. Under the influence of a spring 22 resting against an end face ofsaid stopper 21, the control piston is urged against a shoulder 28formed by a constriction 13e of the passage 13d. Disregarding the devicefor adjusting the stopper 21 within the passage 13d, which adjustingdevice will be described further below, the control piston acts in sucha manner that the fuel leaving the reservoir 11 and passing into thechamber 13b and passages 13c, 13a is by means of the displacement ofpiston 20 to the abutment formed by stopper 21 pressed to apredetermined extent into the passage 13d, and only the remainder isejected throught check valve 14 as stroke delivery into the conduit 19leading to the combustion chamber of the pile driver. Depending on howdeep the stopper 21 is pressed into the bore or passage 13:?! and heldtherein by the adjusting device, a different predetermined deliverydepending on the displacement of the piston 20, is ejected.

The control piston 20 is each time by the spring 22 returned to itsstarting position when the plunger 15 has 3 freed the inlet passage 13a,in which starting position piston 20 abuts shoulder 28.

For purposes of adjusting the extent to which the stopper 21 is movedinto the passage 13d, the arrangement is provided with a pulley 23which, by means of a rope or cable 24 looped therearound may be turnedabout its axis between end abutments 23c, 23d in one or the otherdirection. The circumferential surface of the pulley 23 is furthermoreprovided with (in this instance), a spiral abutment surface or camsurface 23a so that when the pulley 23 is turned the stopper 21 ispressed inwardly and when turned in the opposite direction, is under theinfluence of the spring 22 continuously urged outwardly out of the pumphousing 13 while engaging the cam surface 23a. In order always to bringabout a stepwise turning of the pulley 23 by small steps, a pawl-ratchetmechanism is provided in a central recess of the pulley. Thispawl-ratchet mechanism has associated therewith a predetermined numberof inwardly directed teeth 23b with shoulders and two pawls 26 pivotablyabout pivots 25. Each direction of rotation of the pulley 23 hasassociated therewith one of said pawls. These pawls 26 are in anon-illustrated manner so designed and arranged that when pulling on onestrand of the actuating rope 24, the pulley 23 can with one of its teethbe tilted 'below the end of a pawl 26, which end does not extend intothe path of movement of the tooth. The pawl 26 may after the passage ofthis tooth be so pivoted that its mentioned pawl end extends into thepath of movement of the next tooth and the latter finally abuts the pawlend. Furthermore, the pawl-ratchet mechanism comprises means by whichthe respective pawl, when the pull on the rope is briefly interrupted,returns to a position in which its end pivots outwardly off the path ofthe respective tooth abutting this end, and this tooth can again bemoved below the ratchet.

The pulley 23 runs about an axis 34 in a housing that is not shown. Thepawls 26, having pivot axes 25 firmly established in the housing, arealso provided with auxiliary control levers 29. These control levers 29are swingable at the ends of the pawls 26 about the pivot pins 30 whichjournal the pawls. The one end of the control levers extends in anose-like manner into the area of a locking tooth, ratchet or detent23b, without, however, extending into the path of movement of thisdetent 23b in rest conditon. The control levers project in restcondition of the detent drive on their part likewise in a noselikemanner into the area of a locking tooth or detent 23b, whereby in thiscase the control lever in rest condition extends into the path ofmovement of these locking teeth 23b. A V-formed bent leaf spring 31,which is held by a pin 32 suitably secured to a housing, presses withthe outwardly bent ends 31a thereof against the control levers 29 sothat the contact surface 29a of the control levers lies against anopposing contact surface 26a of the control levers. In the illustratedexample it is to be understood that by pulling on the left strand of therope 24 there is turning of the pulley 23 in the direction of an arrowA. Hereby the left control lever 29 shown in the drawing meets with thenext corresponding locking tooth 23b and during further turning in thedirection of the arrow A swings the control lever 29 into a positionshown in phantom in the drawing. The locking tooth just noted can passfreely along the pawl 26. After the passage, the control lever 29 snapsback under urging of the spring into its fully extended startingposition. During this first swinging in the direction of the arrow A thenose-formed end of the right control lever or pawl 26 has positioneditself in the illustrated rest position, thus the lowest locking tooth23b is moved below this nose end. Thereafter a locking tooth 23b engagesupon an inclined ramp 2% of the right control lever 29 and swings thesame together with the corresponding control lever about the axis 25against the urging of the spring 31 in the phantom-drawn position in aspace between that in the rest position of the lowermost locking tooth23b and the left neighboring locking tooth thereof, be cause the lockingtooth 23b located below in the drawing has already passed the noseduring the beginning of the turning operation. The left neighboringlocking tooth then engages upon the swung-in, contact serving end noseof the right pawl 26. Thereby the pulley is turned by one tooth-pitch.Upon reaching this contact position the pull at the left strand of therope 24 is interrupted, thus the pawl 26 and the control lever 22provided thereon swing back under force of spring 31 in the drawnposition of the parts shown by full lines, corresponding to the restposition. This step shifting can be repeated as often as desired, untilthe pulley 23 strikes with its abutment 230 against the stopper 21.

Also in the opposite direction it is possible to shift stepwise attooth-pitch intervals, whereby the swing operation described for theright shiftand control lever 26 and 29, respectively, occurs for theleft shiftand control lever 26 and 29, respectively.

In this way, it is possible by repeated interrupted pulling on a ropesection of rope 24 to turn the rope pulley 23 always only by steps and,more specifically, by one tooth pitch.

A more detailed description of the pawl-ratchet mechanism appears to besuperfluous, because pawl-ratchet mechanisms of the type involved arewell known as to their construction and operation, and are possible innumerous designs. The specific design of the pawl-ratchet mechanism doesnot teach the invention proper.

What I claim is:

1. In combination with a fuel injection device comprising housing meanshaving inlet passage means for connection with a fuel supply, outletpassage means with check valve means therein for releasing fuel to acombustion chamber, and conduit means interconnecting said inlet andoutlet passage means and including compression chamber means and firstplunger means reciprocable in said compression chamber means forsubjecting fluid therein to pressure; a control device which includes:cylinder means communicating with said conduit means and including firstabutment means, fiuid operable second plunger means reciprocable in saidcylinder means and operable by fuel under pressure in said conduitmeans, second abutment means adjustably arranged in said cylinder meansfor limiting the stroke of said second plunger means in said cylinder inone direction thereof, said first abutment means limiting the stroke ofsaid second plunger means in said cylinder in the opposite direction,spring means adjacent said second plunger means and continuously urgingthe same into abutment with said first abutment means away from saidsecond abutment means, and adjusting means associated with said secondabutment means for adjusting the same, said adjusting means beingmovable by steps independently of the movement of said first plungermeans in said cylinder, said adjusting means including: rotatable cammeans engaging said second abutment means, pawl-ratchet meansoperatively connected to said cam means with the ratchet teeth of thesame circumferential length, said pawl-ratchet means being operable ineither direction, and means operatively connected to said cam means forselectively rotating the same in either direction, the curvature of saidcam means being such that the quantity of fuel delivered by said firstplunger means per stroke through said check valve means changes by thesame amount from step to step when actuating said pawl-ratchet means.

2. An arrangement according to claim 1, Which includes: spring meansinterposed between said second abutment means and said second plungermeans and continuously urging the latter toward said first abutmentmeans.

3. An arrangement according to claim 1, which includes: additionalspring means associated with said first plunger means for continuouslyurging the same to move in a direction out of said compression chamber,and actuating lever means operatively connected to said first plungermeans for moving the same into said compression chamber means againstthe thrust of said additional spring means.

References Cited UNITED STATES PATENTS 1,974,851 9/1934 Hurst 103-37Mercier 103-37 Euwe 103-37 Nerneth 74l26 Timmer et a1. 74l26 Alyea eta1. 23021 WILLIAM L. FREEH, Primary Examiner US. Cl. X.R.

